Influence of population structure on the consumption of systemic antibiotics.

The high level of consumption of systemic antibiotics in our country prompted a study of factors affecting the geographical variations in this consumption. Several parameters explain the uneven distribution of consumption: (a) the epidemiology of the infections, (b) population-dependent factors and (c) factors dependent on the prescribing doctor. The aim of this study was to study population-dependent parameters (type of population and age). A retrospective longitudinal study was made from antibiotic consumption data provided by International Marketing Services (IMS) between 1 January 1996 and 31 December 2000. The consumption indicator used was the number of defined daily doses per 1000 inhabitants per day (DID). Global consumption in regions under study varied by 5.7 DID: Medina del Campo (25.9 DID), Valladolid city (23.4 DID), Laguna de Duero (22.6 DID), Northern Region (22.4 DID), Southern Region (21.4 DID) and lastly Central Region (20.2 DID). The specific consumption per area showed a greater consumption of amoxicillin in the three urban areas, amoxicillin-clavulanic acid and the main macrolides in Medina del Campo, quinolones antibiotics in the Northern Region and tetracyclines and sulphonamides in Valladolid City. Significant area-dependent global consumption differences were observed with the most marked in urban areas. The differences were more marked when studying the geographical distribution of consumption of the commonly used antibiotics.